> fake/locked/misrepresented/stolen items being sold on marketplace sites

100% of the risks you mention are still true with digital transactions. The difference is with cash, you close the door on literal fraudulent transaction claims or stolen accounts. It's vastly safer than digital transactions for in-person sales.

To be blunt - with cash, the buyer can't go home and file an unauthorized/fraud complaint with anyone - the seller has cash-in-hand, is anonymous, and the transaction is non-reversible. That's a benefit for these types of transactions, and one you seem to be overlooking.

If you're selling your couch on Facebook Marketplace - cash is king.

Yes, I understand that buyers can fraudulently file chargebacks with some forms of digital payment. I never said otherwise.

I am disputing your repeated and false claim that there are no fraud vectors with cash.

No payment method prevents fraud.